Refrigerating apparatus



Dec. 1, 1964 c. H. WURTZ 3,159,213

REFRIGERATING APPARATUS Filed Jan. 50, 1962 INVENTOR. CZ/FFOPD H. J VU/PTZ /-//.5 ATTORNEY United States Patent 3,159,213 REFRIGERATING APIARATUS Cliiford H. Wurtz, Dayton, Qhio, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Filed Jan. 30, 1962, Ser. No. 169,894 1 Claim. (til. 165-171) This invention relates to refrigerating apparatus and more particularly to a refrigerant condenser or the like.

The desirability of utilizing heat exchangers made from aluminum tubing has long been recognized but one of the big problems in designing an aluminum heat exchanger is that of providing adequate fin surface without injuring the tubing when attaching fins to the tubing. It is now common practice to manufacure heat exchangers in which wire fins are welded to the outside surfaces of the fluid conducting tubes but it is not practical to weld wire fins to the aluminum tubes as the tube walls are relatively soft and thin and are too frequently damaged when welding fins to the tubes.

It is an object of this invention to provide an aluminum tube type of heat exchanger in which wire fins are firmly held in place on the outer surfaces of the aluminum tubing without any welded connection between the tubing and the fins.

More particularly, it is an object of this invention to place wire fins on opposite sides of a plurality of parallel tubes and to weld or otherwise secure the wire fins together at points intermediate the adjacent parallel tubes so as to clamp the tubes between the wire fins placed on opposite sides of the tubes.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

FIGURE 1 is an elevational view of a heat exchanger embodying my invention;

FIGURE 2 is a fragmentary sectional view taken substantially on line 22 of FIGURE 1;

FIGURE 3 is a view taken substantially in the direction of line 33 of FIGURE 2;

FIGURE 4 is a view somewhat similar to FIGURE 3 but showing a modified wire fin construction; and

FIGURE 5 is a fragmentary view somewhat similar to FIGURE 2 but showing a modified form of fin construction.

Referring now to the drawing wherein preferred forms of the invention have been shown, reference numeral 12 designates aluminum tubing which, for purposes of illustration, has been shown bent into serpentine shape. Wire fins 14 are arranged in contact with opposite sides of the tubing as shown. Any suitable means, such as the mounting brackets 15 shown in dot and dash lines, may be provided for supporting the heat exchanger. While this invention is especially desirable when manufacturing heat exchangers from aluminum material, certain aspects of the invention are equally usable when manufacturing tubing made from other types of materials.

Each of the wire fins 14 comprises a first portion 16 disposed on one side of the parallel portions of the tubing 12 and a second portion 20 is disposed on the opposite side of the tubing 12. After the wire sections 16 and 261 have been arranged to thus straddle the convolutions of the serpentine tube, the one leg of the wire is deformed as shown in FIGURE 2 by applying pressure to the wires at points 22 between adjacent tube sections 12 so as to firmly clamp the tube sections between adjacent wire fin sections 16 and 29 For purposes of illustration the adjacent wire sections have been shown welded together at the points 22 so as to permanently retain the parts in this assembled relationship. In so far as certain aspects of the invention are concerned, any other suitable means, such as clamps or screws, could be used for holding the wire fins in assembled relationship relative to the conduits 12.

As best shown in FIGURE 3 of the drawing, the fins 14 are in the form of round wires whereas for some purposes, fiat wires, such as the wires 30 shown in FIGURE 4, would be used. There are several advantages in using fiat wires over round wires. For one thing, the flat wires provide greater area of contact between the wire fins and the tubes than would be obtained when using round wire fins. Another advantage in using flat wires is that it is easier to spot weld these wires together at the points intermediate the adjacent tube sections.

Whereas FIGURE 2 shows an arrangement in which one spot weld is provided between each pair of adjacent tubes, there are some instances in which one would use two or even more spot welds between adjacent parallel tubes. FIGURE 5 shows such an arrangement in which a pair of spot welds 32 are provided between each pair of tubes. This not only adds strength to the heat exchanger but also further increases the area of contact between the wire fins and the tubes in that the wire fins contact the tubes throughout a greater portion of the circumference.

Due to the softness of the aluminum tubing, the side walls of the tubing are slightly indented where the fins press against the tubing. These indentations increase the turbulence Within the tube and also increase the area of contact between the fins and the outer Walls of the tubing and thereby increase the efficiency of the heat exchanger.

While the embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

In a heat exchanger, a plurality of conduits of readily deformable metal extending in the same general direction, a plurality of wire fins arranged on opposite portions of said conduits, each of said plurality of said fins bridging across a plurality of said conduits in engagement therewith, said wire fins on one of said opposite portions of said conduits having deformed portions in bonded engagement with wire fins on the other of said opposite portions of said conduits whereby said fins are depressed in the outer surface of said conduits for increasing heat exchange contact between conduits and fins.

References Cited in the file of this patent UNITED STATES PATENTS 2,602,649 Goldberg July 8, 1952 2,687,625 Nadler Aug. 31, 1954 2,970,814 Floreen Feb. 7, 1961 FOREIGN PATENTS 452,231 Great Britain July 8, 1935 

